I haven't been able to find much info on this. When the stereo realist fad hit in the 50s, a lot of companies joined in the market even if they weren't known for making cameras. This Delta is a good example. If there are other Deltas, I never heard of them.
Not much of a camera. It was really meant for the drugstore camera crowd, the kind where the lens was marked in zones rather than distance, and the aperture in brightness rather than ƒ/stops. I never used it. I doubt it's previous owners did much with it either.
According to the book, "Glass, Brass and Chrome," this camera was sometimes sold door-to-door.
Camera manual: Orphan Cameras.com